Effects of the 1986-1987 El Nino on Variations of the Vertical and the Tilt.
スポンサーリンク
概要
- 論文の詳細を見る
We attempt to present an explanation for both deflection of the vertical westward 1 ms at Mizusawa and the E-up tilt 50 mas at the Esashi Earth Tides Station during the 1986-1987 El Nino by taking into account bottom pressure which uplifts the northeast Japan plate . The Indo-extratropic Pacific coupling and increase of length of day (LOD) transfer the atmospheric angular momentum (AAM) into the solid Earth in the form of bottom pressure. Ocean loading due to bottom pressure is so small that we can not explain variations of tilt during the El Nino event with the use of ocean tidal loading models . Both the northeast Japan plate and the Pacific plate are assumed to be a thin elastic plate and a moderately thick elastic plate .The Pacific plate bends by uniform pressure over the surface . The ocean plate extends horizontally near the surface relative to the bottom side. The ocean plate induces the bending mo-ment at the edge, which contacts with the island plate. We assume that the bending moment and the modified combined shearing forces are continuous at the boundary between the Pacific plate and the island plate. The island plate bends by the buoyancy forces when the plate is depressed into the lower high density layer, and the compressive stress. With numerical values of uniform bottom pressure 25 Pa over 500 km from the center of the loaded ocean plate, the horizontal length of the island plate taken to be 400 km and 300 km with the elastic thickness to be 30 km, we have deflection of the vertical westwards to be 18 is and 25, us at Mizusawa and the E-up tilt to be 30 mas and 40 mas at Esashi respectively. A thin elastic plate shows large values of bending contrary to the observational results.
- 日本測地学会の論文
日本測地学会 | 論文
- 月衝突盆地補償メカニズムの比較研究
- 重力異常に基づく糸魚川 - 静岡構造線北部の構造解析
- 台湾・竹崎観測室で観測された非等方性潮汐歪
- 電波無反射室におけるGPS測量用アンテナの位相特性の測定(続報)
- 4way ドップラー計測のロック判定方法と軌道上での検証